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    robbibt

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    [–] Lakes, rivers and cannals of The Netherlands [2573x3000] robbibt 38 points ago in MapPorn

    Thankyou for sharing! I made this map... There's an album of zoomed-in images here! https://imgur.com/gallery/GSv7L

    [–] What is the dress code at your GIS position? robbibt 2 points ago in gis

    Australian national government organisation here: on my first day I arrived in a fancy shirt and suit pants, and found the office full of people wearing shorts and t-shirts. I generally wear jeans and short-sleeved button-down shirts to work, which seems to be the go-to for everyone classed as a "scientist" in the organisation (which includes GIS experts and computer scientists). People more involved in policy and management tend to wear more formal dress clothes and suits.

    [–] Checked our terrarium this morning, and surprise: six lizards instead of two! robbibt 4 points ago in reptiles

    We basically attempted to replicate their natural habitat as much as possible: thick damp soil, lots of moss and shrubs, and a bunch of taller palms and ferns and rainforest plants. The great thing about these guys is that they don't need any heat (and cooling only on super hot 40 degree C days), so they're super low maintenance!

    [–] Checked our terrarium this morning, and surprise: six lizards instead of two! robbibt 60 points ago * (lasted edited 24 days ago) in reptiles

    Southern Angle-Headed Dragons (Lophosaurus spinipes), native to the east coast of Australia. They're fantastic lizards, and very easy to look after. These are the parents, Jabberwocky and Valkyrie!

    (The babies were completely unexpected... we have a natural substrate and had seen Valkyrie digging some holes a few months ago, but assumed they were all duds when we found a dried up egg on the surface. A very fun surprise!)

    [–] 29-years of land cover change across Canada's forested ecosystems (animation) robbibt 1 points ago * (lasted edited 24 days ago) in dataisbeautiful

    The individual time-step images here were originally published in a research paper here, but the animation was posted on Twitter directly by the author!

    [–] What gun fired this mystery WWII era shell casing found in Guadalcanal, Solomon Islands? robbibt 2 points ago in whatisthisthing

    Amazing, thankyou! This fits: I measured the primer end because the front is broken and distorted (on a second measure, it's around 0.77 inches with a little oxidation crusting). A few further questions:

    1) What does the "42" number represent? Production year? 2) What kind of purpose would that weapon most commonly be used for in the Pacific? Anti personnel, anti-air etc? It was found washed up on a beach, but that probably doesn't narrow things down much given fighting in the surrounding area took place on land, sea and air. 3) As an Australian with no experience with guns, is the damage at the end simply the result of the bullet being fired?

    [–] What gun fired this mystery WWII era shell casing found in Guadalcanal, Solomon Islands? robbibt 2 points ago in whatisthisthing

    About 15 years ago I found this shell casing washed up on the shore about 20 km northwest of Honiara, Guadalcanal in the Solomon Islands. The area is where some of the most intense battles of the Pacific theatre occurred during WWII, so that narrows down the approximate date. The shell casing is 0.8 inches in diameter, and has "L C 42" stamped on the base (I imagine this means American?)

    What can anyone tell me about what kind of bullet this fired, and the gun used? What does the code mean? And is the damaged end simply the result of the bullet being fired?

    [–] Canada mapped by over 5 million square kilometres of trees and forest [OC] robbibt 1 points ago * (lasted edited 5 months ago) in canada

    I made this as a sequel to a Forests of the USA map I recently posted, and thought /r/Canada might enjoy it! The map was made using a combination of layers from the amazing Hansen et al. 2013 datasets, and elevation data from the Shuttle Radar Topography Mission - all cleaned and prepared in the open-source QGIS software!

    For anyone who would like this as a poster, you can grab a copy here!

    [–] Canada mapped by over 5 million square km / 1.2 billion acres of trees and forest [OC] robbibt 2 points ago in dataisbeautiful

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago * (lasted edited 5 months ago) in dataisbeautiful

    I believe Hansen et al. trained their models directly on Landsat bands 3, 4, 5, and 7 themselves rather than specifically calculating NDVI, but essentially a similar concept!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago in MapPorn

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago * (lasted edited 5 months ago) in dataisbeautiful

    For those curious about how this kind of vegetation mapping is done: the data comes from a group of satellites called Landsat, which have been taking photographs of every 30x30 metre patch of ground on the entire planet since 1972. The photographs include the standard blue, green and red layers of light that we can see with our eyes, but also a whole bunch more that are reflected strongly by plants but are completely invisible to us (e.g. wavelengths like near infrared, short-wave infrared and thermal infrared etc).

    By measuring all these different types of light accurately, you can then teach a computer model (in this case, an aptly-named "decision tree"... but "random forest" models are popular too!) to recognise what combinations of light indicate that trees are growing below. By applying those models to every 30x30 metre patch of ground using a supercomputer, you can then map out the locations of forests and trees across the entire planet!

    [–] Canada mapped by over 5 million square kilometres of trees and forests [OC] robbibt 1 points ago in dataisbeautiful

    A few weeks ago I posted Forests of the USA, and got lots of requests for other parts of the world... including literally hundreds for Canada! To make this map I used R code to download vegetation layers from the amazing Hansen et al. 2013 datasets, used a median filter to remove noise and spatial Landsat artefacts, and included local topography using a SRTM 90m resolution digital elevation data overlay. Visualised using the open-source QGIS software!